ECT’s Universal PRT Fitting utilizes o-ring connections to ensure a vacuum-tight seal. The soil vapor sample is drawn through the expendable point holder, through the PRT fitting and into the sample tubing. ECT’s Stainless Steel PRT Fitting accepts various tubing sizes: 1/4-inch OD, 3/8-inch OD and 1/2-inch OD. Used only with SVPT2 (1.25 in.) & SVPT13 (1.5-in.).